(C) Copyright 1989 Texas Instruments Incorporated. A portion of the disclosure of this patent document contains material which is subject to copyright protection. The copyright owner has no objection to the facsimile reproduction by anyone of the patent disclosure, as it appears in the Patent and Trademark Office patent file or records, but otherwise reserves all copyright rights whatsoever.
This invention generally relates to communications systems and integrated electronic devices used therein, and more particularly, to improved communications systems and improved apparatus and methods for use in such systems.
Local area networks (LANs) have become widely accepted and used within many and various industries as a way to interconnect many work stations and/or personal computers (PCs) to allow them to share resources such as data and applications without the need for an expensive mainframe computer and its associated multiple attached terminals. One widely accepted LAN arrangement is an xe2x80x9cEthernetxe2x80x9d LAN, which is defined in the IEEE 802.3 standard.
With the widespread acceptance of LANs and the continuing acceleration of technology, the demand for LAN arrangements with higher and higher transfer rates continues unabated. Two 100 megabit per second (Mbps) LANs are extending the reach of the installed base of 10 Mbps Ethernet LANs; they are the IEEE 802.3u standard for xe2x80x9cFast Ethernetxe2x80x9d or 100 MBITS CSMA/CD and the other is the IEEE 802.12 standard for 100 VG-AnyLAN or Demand Priority. In addition, switched Ethernet has been proposed to meet this demand. The emergence of switched Ethernet promises to increase network bandwidth to the desktop without the need to replace network cabling or adapters. However, for this promise to be fulfilled the cost of switching hubs needs to fall towards the cost of conventional repeater hubs.
The present invention provides an ethernet LAN switch capable of performing other network functions that allows for improved communications systems and methods for use in such systems and improved apparatus that support this demand in a cost effective and versatile manner.
Generally, and in one form of the present invention, an improved communications system having a circuit with a plurality of communications ports capable of multispeed operation and operable in a first mode that includes address resolution and in a second mode that excludes address resolution is provided.
An improved communications system having a first memory, a plurality of protocol handlers, a bus connected to said protocol handlers, a second memory connected to said bus, and a memory controller connected to said bus and said second memory for selectively comparing addresses, transferring data between said protocol handlers and said second memory, and transferring data between said second memory and said first memory is provided.
The present invention provides a local area network controller having a first circuit with a plurality of communications ports capable of multispeed operation and operable in a first mode that includes address resolution and in a second mode that excludes address resolution, and an address lookup circuit interconnected to said first circuit.
The present invention provides an integrated circuit having a plurality of protocol handlers, a bus connected to said protocol handlers, a memory connected to said bus, and a memory controller connected to said bus and said memory for selectively comparing addresses, transferring data between said protocol handlers and said memory, and transferring data between said memory and an external memory.
The present invention provides an ethernet switch having a plurality of protocol handlers each having a serializer and deserializer and a holding latch, a bus connected to said holding latches, a memory connected to said bus, and a memory controller connected to said bus and said memory for selectively comparing addresses, transferring data between said latches and said memory and transferring data between said memory and an external memory. The present invention provides a single chip network protocol handler having a first protocol handler having a serializer and deserializer and a holding latch for operating at a first bit rate, a second protocol handler having a serializer and deserializer and a holding latch for operating at a second bit rate, and a controller connected to said protocol handlers for selecting one of said protocol handlers based on preselected control signals.
The present invention provides an address matching circuit having a memory for containing addresses arranged in a linked list, a first state machine for creating and updating the linked list of addresses, a second state machine for providing routing information for a selected address based upon the linked list of addresses, and a bus watcher circuit for monitoring data traffic on a bus to detect addresses.
The present invention provides an address matching circuit having an address memory with an address memory bus, a bus watcher circuit connected to an external data bus for detecting addresses, an arbiter connected to said bus watcher and said address memory bus for generating control signals for prioritizing access to said address memory bus, and a plurality of state machines selectively connectable to said address memory bus in response to said control signals and for providing routing information based upon matching a detected address with an address stored in said address memory, for adding, updating or deleting addresses and associated routing information in said address memory, and for searching for an address in said address memory.
It is an object of the present invention to provide apparatus and methods for hardware control of network switching functions rather than CPU based control.
It is an object of the present invention to provide apparatus and methods for hardware control based communications systems.
It is an object of the present invention to provide simpler apparatus and methods for networking.
It is an object of the present invention to provide lower cost apparatus and methods for networking.
It is an object of the present invention to provide highly integrated apparatus and methods for networking.
It is an object of the present invention to provide simpler and lower cost apparatus and methods for communications systems.